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Gaff J, Octaviana F, Jackaman C, Kamerman P, Papadimitriou J, Lee S, Mountford J, Price P. Expression in skin biopsies supports genetic evidence linking CAMKK2, P2X7R and P2X4R with HIV-associated sensory neuropathy. J Neurovirol 2023; 29:241-251. [PMID: 37166584 PMCID: PMC10404215 DOI: 10.1007/s13365-023-01134-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 04/05/2023] [Accepted: 04/07/2023] [Indexed: 05/12/2023]
Abstract
HIV-associated sensory neuropathy (HIV-SN) affects 14-38% of HIV+ individuals stable on therapy with no neurotoxic drugs. Polymorphisms in CAMKK2, P2X7R and P2X4R associated with altered risk of HIV-SN in Indonesian and South African patients. The role of CaMKK2 in neuronal repair makes this an attractive candidate, but a direct role for any protein is predicated on expression in affected tissues. Here, we describe expression of CaMKK2, P2X7R and P2X4R proteins in skin biopsies from the lower legs of HIV+ Indonesians with and without HIV-SN, and healthy controls (HC). HIV-SN was diagnosed using the Brief Peripheral Neuropathy Screen. Biopsies were stained to detect protein gene product 9.5 on nerve fibres and CaMKK2, P2X7R or P2X4R, and were examined using 3-colour sequential scanning confocal microscopy. Intraepidermal nerve fibre densities (IENFD) were lower in HIV+ donors than HC and correlated directly with nadir CD4 T-cell counts (r = 0.69, p = 0.004). However, IENFD counts were similar in HIV-SN+ and HIV-SN- donors (p = 0.19) and so did not define neuropathy. CaMKK2+ cells were located close to dermal and epidermal nerve fibres and were rare in HC and HIV-SN- donors, consistent with a role for the protein in nerve damage and/or repair. P2X7R was expressed by cells in blood vessels of HIV-SN- donors, but rarely in HC or HIV-SN+ donors. P2X4R expression by cells in the epidermal basal layer appeared greatest in HIV-SN+ donors. Overall, the differential expression of CaMKK2, P2X7R and P2X4R supports the genetic evidence of a role for these proteins in HIV-SN.
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Affiliation(s)
- Jessica Gaff
- Curtin Medical School, Curtin University, Bentley, 6102, Australia
| | - Fitri Octaviana
- Neurology Department, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
- Neurology Department, Cipto Mangunkusumo Hospital, Jakarta, Indonesia
| | - Connie Jackaman
- Curtin Medical School, Curtin University, Bentley, 6102, Australia
- Curtin Health Innovation Research Institute, Bentley, Australia
| | - Peter Kamerman
- School of Physiology, University of Witwatersrand, Johannesburg, South Africa
| | | | - Silvia Lee
- Curtin Medical School, Curtin University, Bentley, 6102, Australia
- Department of Microbiology, Pathwest Laboratory Medicine, Perth, Australia
| | | | - Patricia Price
- Curtin Medical School, Curtin University, Bentley, 6102, Australia.
- Neurology Department, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia.
- Curtin Health Innovation Research Institute, Bentley, Australia.
- School of Physiology, University of Witwatersrand, Johannesburg, South Africa.
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Sluyter R, Adriouch S, Fuller SJ, Nicke A, Sophocleous RA, Watson D. Animal Models for the Investigation of P2X7 Receptors. Int J Mol Sci 2023; 24:ijms24098225. [PMID: 37175933 PMCID: PMC10179175 DOI: 10.3390/ijms24098225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 04/21/2023] [Accepted: 04/27/2023] [Indexed: 05/15/2023] Open
Abstract
The P2X7 receptor is a trimeric ligand-gated cation channel activated by extracellular adenosine 5'-triphosphate. The study of animals has greatly advanced the investigation of P2X7 and helped to establish the numerous physiological and pathophysiological roles of this receptor in human health and disease. Following a short overview of the P2X7 distribution, roles and functional properties, this article discusses how animal models have contributed to the generation of P2X7-specific antibodies and nanobodies (including biologics), recombinant receptors and radioligands to study P2X7 as well as to the pharmacokinetic testing of P2X7 antagonists. This article then outlines how mouse and rat models have been used to study P2X7. These sections include discussions on preclinical disease models, polymorphic P2X7 variants, P2X7 knockout mice (including bone marrow chimeras and conditional knockouts), P2X7 reporter mice, humanized P2X7 mice and P2X7 knockout rats. Finally, this article reviews the limited number of studies involving guinea pigs, rabbits, monkeys (rhesus macaques), dogs, cats, zebrafish, and other fish species (seabream, ayu sweetfish, rainbow trout and Japanese flounder) to study P2X7.
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Affiliation(s)
- Ronald Sluyter
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia
| | - Sahil Adriouch
- UniRouen, INSERM, U1234, Pathophysiology, Autoimmunity, and Immunotherapy, (PANTHER), Univ Rouen Normandie, University of Rouen, F-76000 Rouen, France
| | - Stephen J Fuller
- Sydney Medical School Nepean, Faculty of Medicine and Health, The University of Sydney, Nepean Hospital, Kingswood, NSW 2750, Australia
| | - Annette Nicke
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, LMU Munich, 80336 Munich, Germany
| | - Reece A Sophocleous
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia
| | - Debbie Watson
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia
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McEwan TBD, Sophocleous RA, Cuthbertson P, Mansfield KJ, Sanderson-Smith ML, Sluyter R. Autocrine regulation of wound healing by ATP release and P2Y 2 receptor activation. Life Sci 2021; 283:119850. [PMID: 34314735 DOI: 10.1016/j.lfs.2021.119850] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 07/05/2021] [Accepted: 07/17/2021] [Indexed: 12/19/2022]
Abstract
AIMS Application of exogenous nucleotides can modulate wound healing via the activation of purinergic receptors. However, evidence for the release of endogenous nucleotides and the subsequent activation of purinergic receptors in this process has not been well defined. Therefore, the current study aimed to investigate wound-mediated nucleotide release and autocrine purinergic signalling during HaCaT keratinocyte wound closure following scratch injury. MAIN METHODS An in vitro scratch wound apparatus was employed to study wound healing over 24-h in the presence of modulators of ATP release, P2 receptors and pathways downstream of P2 receptor activation. KEY FINDINGS Adenosine 5'-triphosphate (ATP) was released from scratched cells. The ectonucleotidase apyrase and pharmacological inhibition of the nucleotide release hemichannel, pannexin-1, decreased wound closure over time. The non-selective P2Y receptor antagonist suramin and the selective P2Y2 receptor antagonist AR-C118925XX, but not other P2 antagonists, decreased wound closure. AR-C118925XX decreased wound closure in a concentration-dependent fashion. However, exogenous P2Y2 receptor agonists, ATP or uridine 5'-triphosphate, did not enhance wound closure. PCR and immunoblotting confirmed P2Y2 receptor expression in HaCaT cells. U73122, a phospholipase C antagonist, and 2-aminoethoxydiphenylborate, an inositol 1,4,5-trisphosphate receptor-sensitive Ca2+-release channel antagonist, decreased wound closure consistent with P2Y2 receptor activation. Absence of extracellular or intracellular Ca2+ or inhibition of intracellular Ca2+-release also impaired wound closure. SIGNIFICANCE These data describe a novel autocrine signalling mechanism in which wound-mediated release of endogenous ATP in response to mechanical scratching of HaCaT cells activates P2Y2 receptors to facilitate wound closure.
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Affiliation(s)
- T B-D McEwan
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia; Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
| | - R A Sophocleous
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia; Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
| | - P Cuthbertson
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia; Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
| | - K J Mansfield
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia; School of Medicine, University of Wollongong, Wollongong, NSW 2522, Australia
| | - M L Sanderson-Smith
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia; Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
| | - R Sluyter
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia; Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia.
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Pacheco P, Galvão R, Faria A, Von Ranke N, Rangel M, Ribeiro T, Bello M, Rodrigues C, Ferreira V, da Rocha D, Faria R. 8-Hydroxy-2-(1H-1,2,3-triazol-1-yl)-1,4-naphtoquinone derivatives inhibited P2X7 Receptor-Induced dye uptake into murine Macrophages. Bioorg Med Chem 2019; 27:1449-1455. [DOI: 10.1016/j.bmc.2018.11.036] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 11/20/2018] [Accepted: 11/26/2018] [Indexed: 12/26/2022]
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The therapeutic potential of purinergic signalling. Biochem Pharmacol 2018; 151:157-165. [DOI: 10.1016/j.bcp.2017.07.016] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 07/18/2017] [Indexed: 01/05/2023]
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Burnstock G, Knight GE. The potential of P2X7 receptors as a therapeutic target, including inflammation and tumour progression. Purinergic Signal 2018; 14:1-18. [PMID: 29164451 PMCID: PMC5842154 DOI: 10.1007/s11302-017-9593-0] [Citation(s) in RCA: 171] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 11/01/2017] [Indexed: 12/22/2022] Open
Abstract
Seven P2X ion channel nucleotide receptor subtypes have been cloned and characterised. P2X7 receptors (P2X7R) are unusual in that there are extra amino acids in the intracellular C terminus. Low concentrations of ATP open cation channels sometimes leading to cell proliferation, whereas high concentrations of ATP open large pores that release inflammatory cytokines and can lead to apoptotic cell death. Since many diseases involve inflammation and immune responses, and the P2X7R regulates inflammation, there has been recent interest in the pathophysiological roles of P2X7R and the potential of P2X7R antagonists to treat a variety of diseases. These include neurodegenerative diseases, psychiatric disorders, epilepsy and a number of diseases of peripheral organs, including the cardiovascular, airways, kidney, liver, bladder, skin and musculoskeletal. The potential of P2X7R drugs to treat tumour progression is discussed.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical School, Rowland Hill Street, London, NW3 2PF, UK.
- Department of Pharmacology and Therapeutics, The University of Melbourne, Melbourne, Australia.
- Florey Institute of Neuroscience and Mental Health, Parkville, Melbourne, Australia.
| | - Gillian E Knight
- Autonomic Neuroscience Centre, University College Medical School, Rowland Hill Street, London, NW3 2PF, UK
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7
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Geraghty NJ, Mansfield KJ, Fuller SJ, Watson D, Sluyter R. The P2X7 receptor is not essential for development of imiquimod-induced psoriasis-like inflammation in mice. Purinergic Signal 2017; 13:405-415. [PMID: 28597172 PMCID: PMC5714832 DOI: 10.1007/s11302-017-9569-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Accepted: 04/13/2017] [Indexed: 02/06/2023] Open
Abstract
Psoriasis is a chronic inflammatory skin disorder, characterised by epidermal hyperplasia (acanthosis) and leukocyte infiltration of the skin. Current therapies are inadequate, highlighting the need for new therapeutic targets. The P2X7 receptor is implicated in the pathogenesis of psoriasis. This study investigated the role of P2X7 in imiquimod (IMQ)-induced psoriasis-like inflammation. Topically applied IMQ caused twofold greater ear swelling in BALB/c mice compared to C57BL/6 mice, which encode a partial loss-of-function missense mutation in the P2RX7 gene. However, there was no difference in histological skin pathology (acanthosis and leukocyte infiltration) between the two strains. IMQ treatment up-regulated P2X7 expression in skin from both mouse strains. Additionally, IMQ induced ATP release from cultured human keratinocytes, a process independent of cell death. Injection of the P2X7 antagonist Brilliant Blue G (BBG) but not A-804598 partly reduced ear swelling compared to vehicle-injected control mice. Neither antagonist altered skin pathology. Moreover, no difference in ear swelling or skin pathology was observed between C57BL/6 and P2X7 knock-out (KO) mice. Flow cytometric analysis of IMQ-treated skin from C57BL/6 and P2X7 KO mice demonstrated similar leukocyte infiltration, including neutrophils, macrophages and T cells. In conclusion, this study demonstrates that P2X7 is not essential for development of IMQ-induced psoriasis-like inflammation but does not exclude a role for this receptor in psoriasis development in humans or other mouse models of this disease.
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Affiliation(s)
- Nicholas J Geraghty
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia
- Centre for Medical and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
| | - Kylie J Mansfield
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
- School of Medicine, University of Wollongong, Wollongong, NSW, Australia
| | - Stephen J Fuller
- Sydney Medical School, University of Sydney, Sydney, NSW, Australia
| | - Debbie Watson
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia
- Centre for Medical and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
| | - Ronald Sluyter
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia.
- Centre for Medical and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia.
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia.
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8
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Burnstock G. Purinergic Signalling: Therapeutic Developments. Front Pharmacol 2017; 8:661. [PMID: 28993732 PMCID: PMC5622197 DOI: 10.3389/fphar.2017.00661] [Citation(s) in RCA: 263] [Impact Index Per Article: 37.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 09/05/2017] [Indexed: 12/15/2022] Open
Abstract
Purinergic signalling, i.e., the role of nucleotides as extracellular signalling molecules, was proposed in 1972. However, this concept was not well accepted until the early 1990's when receptor subtypes for purines and pyrimidines were cloned and characterised, which includes four subtypes of the P1 (adenosine) receptor, seven subtypes of P2X ion channel receptors and 8 subtypes of the P2Y G protein-coupled receptor. Early studies were largely concerned with the physiology, pharmacology and biochemistry of purinergic signalling. More recently, the focus has been on the pathophysiology and therapeutic potential. There was early recognition of the use of P1 receptor agonists for the treatment of supraventricular tachycardia and A2A receptor antagonists are promising for the treatment of Parkinson's disease. Clopidogrel, a P2Y12 antagonist, is widely used for the treatment of thrombosis and stroke, blocking P2Y12 receptor-mediated platelet aggregation. Diquafosol, a long acting P2Y2 receptor agonist, is being used for the treatment of dry eye. P2X3 receptor antagonists have been developed that are orally bioavailable and stable in vivo and are currently in clinical trials for the treatment of chronic cough, bladder incontinence, visceral pain and hypertension. Antagonists to P2X7 receptors are being investigated for the treatment of inflammatory disorders, including neurodegenerative diseases. Other investigations are in progress for the use of purinergic agents for the treatment of osteoporosis, myocardial infarction, irritable bowel syndrome, epilepsy, atherosclerosis, depression, autism, diabetes, and cancer.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical SchoolLondon, United Kingdom
- Department of Pharmacology and Therapeutics, The University of Melbourne, MelbourneVIC, Australia
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9
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Geraghty NJ, Belfiore L, Ly D, Adhikary SR, Fuller SJ, Varikatt W, Sanderson-Smith ML, Sluyter V, Alexander SI, Sluyter R, Watson D. The P2X7 receptor antagonist Brilliant Blue G reduces serum human interferon-γ in a humanized mouse model of graft-versus-host disease. Clin Exp Immunol 2017; 190:79-95. [PMID: 28665482 DOI: 10.1111/cei.13005] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/23/2017] [Indexed: 01/31/2023] Open
Abstract
Graft-versus-host disease (GVHD) remains a major problem after allogeneic haematopoietic stem cell transplantation, a curative therapy for haematological malignancies. Previous studies have demonstrated a role for the adenosine triphosphate (ATP)-gated P2X7 receptor channel in allogeneic mouse models of GVHD. In this study, injection of human peripheral blood mononuclear cells (PBMCs) into immunodeficient non-obese diabetic-severe combined immunodeficiency-interleukin (NOD-SCID-IL)-2Rγnull (NSG) mice established a humanized mouse model of GVHD. This model was used to study the effect of P2X7 blockade in this disease. From five weeks post-PBMC injection, humanized mice exhibited clinical signs and histopathology characteristic of GVHD. The P2X7 antagonist, Brilliant Blue G (BBG), blocked ATP-induced cation uptake into both murine and human cells in vitro. Injection of BBG (50 mg/kg) into NSG mice did not affect engraftment of human leucocytes (predominantly T cells), or the clinical score and survival of mice. In contrast, BBG injection reduced circulating human interferon (IFN)-γ significantly, which was produced by human CD4+ and CD8+ T cells. BBG also reduced human T cell infiltration and apoptosis in target organs of GVHD. In conclusion, the P2X7 antagonist BBG reduced circulating IFN-γ in a humanized mouse model of GVHD supporting a potential role for P2X7 to alter the pathology of this disease in humans.
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Affiliation(s)
- N J Geraghty
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia.,Centre for Medical and Molecular Biosciences, University of Wollongong, Wollongong, NSW, Australia.,Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
| | - L Belfiore
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia.,Centre for Medical and Molecular Biosciences, University of Wollongong, Wollongong, NSW, Australia.,Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
| | - D Ly
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia.,Centre for Medical and Molecular Biosciences, University of Wollongong, Wollongong, NSW, Australia.,Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
| | - S R Adhikary
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia.,Centre for Medical and Molecular Biosciences, University of Wollongong, Wollongong, NSW, Australia.,Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
| | - S J Fuller
- Sydney Medical School Nepean, University of Sydney, Nepean Hospital, Penrith, NSW, Australia
| | - W Varikatt
- Sydney Medical School Westmead, University of Sydney, Westmead Hospital, NSW, Australia.,Institute for Clinical Pathology and Medical Research, Westmead, NSW Health Pathology, Australia
| | - M L Sanderson-Smith
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia.,Centre for Medical and Molecular Biosciences, University of Wollongong, Wollongong, NSW, Australia.,Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
| | - V Sluyter
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia.,Centre for Medical and Molecular Biosciences, University of Wollongong, Wollongong, NSW, Australia.,Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
| | - S I Alexander
- Children's Hospital at Westmead, Westmead, NSW, Australia
| | - R Sluyter
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia.,Centre for Medical and Molecular Biosciences, University of Wollongong, Wollongong, NSW, Australia.,Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
| | - D Watson
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, Australia.,Centre for Medical and Molecular Biosciences, University of Wollongong, Wollongong, NSW, Australia.,Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
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Abstract
The P2X7 receptor is a trimeric ion channel gated by extracellular adenosine 5'-triphosphate. The receptor is present on an increasing number of different cells types including stem, blood, glial, neural, ocular, bone, dental, exocrine, endothelial, muscle, renal and skin cells. The P2X7 receptor induces various downstream events in a cell-specific manner, including inflammatory molecule release, cell proliferation and death, metabolic events, and phagocytosis. As such this receptor plays important roles in heath and disease. Increasing knowledge about the P2X7 receptor has been gained from studies of, but not limited to, protein chemistry including cloning, site-directed mutagenesis, crystal structures and atomic modeling, as well as from studies of primary tissues and transgenic mice. This chapter focuses on the P2X7 receptor itself. This includes the P2RX7 gene and its products including splice and polymorphic variants. This chapter also reviews modulators of P2X7 receptor activation and inhibition, as well as the transcriptional regulation of the P2RX7 gene via its promoter and enhancer regions, and by microRNA and long-coding RNA. Furthermore, this chapter discusses the post-translational modification of the P2X7 receptor by N-linked glycosylation, adenosine 5'-diphosphate ribosylation and palmitoylation. Finally, this chapter reviews interaction partners of the P2X7 receptor, and its cellular localisation and trafficking within cells.
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Affiliation(s)
- Ronald Sluyter
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, 2522, Australia. .,Centre for Medical and Molecular Bioscience, University of Wollongong, Wollongong, NSW, 2522, Australia. .,Illawarra Health and Medical Research Institute, Wollongong, NSW, 2522, Australia.
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N-Alkyl-Substituted Isatins Enhance P2X7 Receptor-Induced Interleukin-1β Release from Murine Macrophages. Mediators Inflamm 2016; 2016:2097219. [PMID: 27524862 PMCID: PMC4972911 DOI: 10.1155/2016/2097219] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Accepted: 06/23/2016] [Indexed: 11/17/2022] Open
Abstract
Extracellular adenosine 5'-triphosphate (ATP) activates the P2X7 receptor channel to induce the rapid release of the proinflammatory cytokine, interleukin- (IL-) 1β, from macrophages. Microtubule rearrangements are thought to be involved in this process. Some isatin derivatives alter microtubules and display anticancer activities. The current study investigated the effect of isatin and seven structurally diverse isatin derivatives on P2X7-mediated IL-1β release from murine J774 macrophages. ATP-induced IL-1β and lactate dehydrogenase (LDH) release were assessed by specific colorimetric assays. P2X7 activity was determined by flow cytometric measurements of ATP-induced cation dye uptake. Cytotoxicity of isatin derivatives was determined using a tetrazolium-based colorimetric assay. ATP caused rapid IL-1β release in a concentration-dependent manner, and this process was completely impaired by the P2X7 antagonist, AZ10606120. In contrast, 5,7-dibromo-N-(p-methoxybenzyl)isatin (NAI) and 3-{4-[5,7-dibromo-1-(4-methoxybenzyl)-2-oxoindolin-3-ylidenamino]phenyl}propanoic acid (NAI-imine) enhanced P2X7-induced IL-1β release by twofold compared to that of isatin and the parent molecule, 5,7-dibromoisatin. NAI and NAI-imine had minimal effect on P2X7-induced dye uptake and LDH release. In contrast, 24-hour incubation with NAI and NAI-imine (in the absence of exogenous ATP) induced macrophage death in a concentration-dependent manner. In conclusion, this study demonstrates that N-alkyl-substituted isatins enhance P2X7 receptor-induced IL-1β release from murine macrophages. Thus, in addition to direct anticancer effects, these compounds may also impact inflammatory and immune cells within the tumor microenvironment.
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